Drums of War Review: Perhaps the fantasy battle game you were looking for.

About Drums of War, from BoardGameGeek:

Set in a fantasy world, Drums of War puts each player in charge of an army represented by an asymmetrical deck of cards, led by a commanding hero. Cards are deployed on the battlefield, in the form of units, equipment or tactics, which decimate the deck for each action they perform. In two-player or solo games, Drums of War offers fast-paced, tactical games lasting 30 minutes. Each player has a deck of 38 cards, from which we will have to draw a certain number, according to the hero we are going to use in the battle. Some heroes force us to draw them at random, while others allow us to choose them. Along the game, we alternatively deploy cards from our hand to the battlefield with the particularity that, to deploy a card, we will have to pay its cost with other cards from our hand. Retired cards, except for specific ability effects, do not return to play during the game… you will have to choose wisely! Once both players pass, combat takes place between the units deployed on the battlefield. To win the game you must cause the opponent's hero as many wounds as his life value indicates, before running out of cards to recover your hand. -description from the publisher Ambientado en un mundo de fantasía, Tambores de Guerra pone a cada jugador al frente de un ejército representado por un mazo de cartas asimétrico, comandado por un héroe al mando. Las cartas se despliegan sobre el campo de batalla, en forma de unidades, equipo o tácticas, que van diezmando el mazo por cada acción que realicen. En partidas para dos jugadores o en solitario, Tambores de Guerra ofrece partidas rápidas y tácticas de 30 minutos de duración. Para ello, cada jugador cuenta con un mazo de 38 cartas, de las que habremos tenido que retirar cierto número, según el héroe que vamos a utilizar en la batalla. Algunos héroes nos obligan a retirarlas al azar, mientras otros nos permiten elegirlas. Durante la partida, desplegamos alternativamente cartas de la mano al campo de batalla con la particularidad de que, para desplegar una carta tendremos que pagar su coste con otras cartas de nuestra mano. Las cartas retiradas, salvo efectos de habilidades concretas, no vuelven al juego durante la partida… ¡tendrás que elegir bien! Una vez que ambos jugadores pasan se produce el combate entre las unidades desplegadas en el campo de batalla. Para obtener la victoria debemos causar al héroe rival tantas heridas como indica su valor de vida, antes de quedarnos sin cartas para recuperar nuestra mano. -description from the publisher (Spanish)